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PROCESS OF SECURING DENTAL SUCTION VALVES T0 PLATES.

NO.' 506,76Z. PatentedOet. 17, 18-93.

UNITED STATES PATENT OFFICE.

ALFRED E. AHRENS, OF STRATFORD, CANADA.

PROCESS OF SECURING DENTAL SUCTION-VALVES TO PLATES.

SPECIFICATION forming part of Letters Patent No. 506,762, dated October 17, 1893.

Application filed May 18, 1893- Serial No. $74,650. (N0 specimens.)

To all whom it may concern.-

Be it known that I, ALFRED EMMANUEL AHRENS, of the city of Stratford, in the county of Perth, in the Province of Ontario, Canada, have invented a certain new and Improved Process for Securing Dental Suction-Valves to Plates, of which the following is a specification.

The object of the invention is to provide a process for securing a dental suction valve to the plate in the exact position that the shape of the mouth calls for, and it consists in cementing the rubber disk to the mouth cast or mold exactly in the position called for by the shape of the month, then placing the plate in position on the valve and vulcanizing the two together, substantially as hereinafter more particularly explained.

Figure 1, is a view of a mouth cast or mold with the Valve in position. Fig. 2, is a view of the plate after it has been removed from the vulcanizer.

.The great objection in using a dental suction valve is the difficulty of securing the valve exactly in the proper position.

By the adoption of my invention, I am able to locate the valve exactly in the. position called for bythe formation of a mouth. This formation should be accurately taken by the mold A, which will show the exact position that the valve should be located. This valve B, I make of non-vulcanizing rubber covered with a metal casing a, which protects the edge of the valve and covers all of one side, ex-' cept a small space b, exactly in the center of the disk. The proper point for the location of this valve having been selected on the mold A, I place on the said mold the valve B, rubber face down, securing it in position by a few drops of chloroform. I then place the plate 0, in position on the mold and proceed with the work in the usual way. The rubber space I), being next to the plate 0, the valve B, becomes cemented to the plate 0, it havthe side of the valve in metal, next in cementing the rubber disk to the mouth cast or mold exactly in the position called for by the shape of the month, then placing the plate in position on the valve and vulcanizing the two'together, substantially as and for the purpose specified.

Stratford, April 22, 1893.

ALFRED E. AHRENS. In presence of- P. P. HAMILTON, JOHN E. HARDING. 

